Since 1910, the Smithsonian's National Museum of Natural History has inspired curiosity and learning about the natural world and our place in it.

Fossils

06/12/2015

Two enormous dinosaurs—Triceratops and Tyrannosaurus rex—reign over the exhibition, “The Last American Dinosaurs: Discovering a Lost World.” The show tells the story of non-avian dinosaurs’ final years in western North America through an extraordinary diversity of fossil animals and plants from the Hell Creek Formation in North Dakota, South Dakota and Montana. (Photo by Donald E. Hurlbert / Smithsonian Institution).

Taking children through a museum can create lifelong memories, but sometimes the excitement can be overwhelming! While T. rex is certainly for all ages, here are some tips for children, ages 4-11, to experience the most in our exhibit The Last American Dinosaurs: Discovering a Lost World.

1. Growing Up Triceratops-Exploring Diet and Growth.

The gargantuan fossilized skeleton of the triceratops will always fascinate children, but what can they learn about the life of this extinct creature from its bones? This exhibit explores how what these animals ate and how they grew. Ask kids to look at the teeth of the Triceratops, what kind of food do you think they ate, and how does this compare with a human diet?Examine the baby and adolescent Triceratops skulls and notice how quickly they grow, how quickly do humans grow? How does the Triceratops change as it gets older? How do people change as they get older?

2. Potty Training the T. rex-More than bones can be fossilized.

Put a new spin on an old favorite by exploring other remnants from the T. rex’s life. Looking at eating habits again, ask kids to find two clues that show what the T. rex ate. The T.rex’s teeth may be the obvious clue, but remember that what goes in must come out! A fossil as rare as its creator, see if children can find the fossilized T. rex corprolite (fossilized poop), complete with bone fragments.

Coprolite replica from 3D scanning, Tyrannosaurid dinosaur. Late Cretaceous Period, 66-68 million years ago. Original in the Royal Saskatchewan Museum, Regina, Saskatchewan, Canada.

3. I Spy an Extinct World- We have more in common with the world of Dinosaurs than you think.

A vivid mural covers a wall with images of an ancient world full of unknown (and some familiar) plants, animals, and insects. Engage your young visitors in a rousing game of “I Spy,” and see how many creatures they can find hidden amongst the leaves. How many of those creatures seem familiar today; did you see that dragonfly? Consider the mammals, what’s different about them? See how many organisms they can find! What about this ancient environment looks the same as today? What’s different?

4. How to become a Fossil-How luck, and a dozen other factors, create fossils.

We see fossils all the time in the museum, but where do they come from, and how do they get here after millions of years? Find out while having fun with the revamped version of the Smithsonian original “How to Become a Fossil” arcade game. People of all ages can make choices that will determine their likelihood at becoming a fossil, but ultimately it’s up to luck!

Screenshot of the arcade-style game “How to Become a Fossil,” based on the original 1988 computer interactive program created by Dr. Kay Behrensmeyer, Roger Cutler, and Alan Cutler.

Now that you know how fossils are made, don’t miss the map of North American dinosaur fossil sites behind the FossiLab. Try to locate where the nearest fossil found to where their home lies. You just might have dinosaurs in your own back yard!

5. One thing Paleontologists Never go Without-Exploring Careers in Science.

Once you know where you’re most likely to find a fossil, you’re going to need to learn how scientists work to dig them out and study them. Journey to the Hell Creek Formation in Montana and North Dakota and find out what it’s like for paleontologists to work in the field. For example, why is toilet paper important to paleontologists? Ask your young visitors to search for the answer, in doing so they’ll explore the tools a paleontologist uses and stories of discoveries. They use toilet paper for more than you might think! What other tools do they use? Some of them are in the exhibit cases, but there are also videos of scientists talking about their adventures out in the field.

Important tools for a paleontologist! What do you use in the field? Share in the comments below.

Just because the dinosaurs are extinct doesn’t mean fun has to be! For an even more hands-on experience explore Q?rius for teens and Q?rius Jr. for K-8, interactive learning spaces where visitors can hold specimens in our collections, like fossils!

By Paige Rylander, Public Affairs Intern, National Museum of Natural History, with special thanks to NMNH educator Amy Bolton

02/22/2015

As our Museum writers, scientists, and exhibition developers produce the script for the new Fossil Hall, they’re discovering lots of fascinating stories about how life evolved. We’ll be sharing some of our favorites here.

Passing cargo ships are a common sight at one of the fossil dig sites along the Panama Canal. Photo by Juliana Olsson.

In March 2014, I visited a fossil excavation project along the Panama Canal run by the Smithsonian Tropical Research Institute. We don’t normally search for fossils in the lush tropics, but the current expansion project to widen the channels and build new locks is exposing more rocks. This gives scientists a rare opportunity to find otherwise inaccessible fossils. It was both strange and wonderful to stand on the 100-year-old canal and look at fossils that were far older. Panama’s story is essentially the tale of multiple waves of invasive species. The formation of this narrow strip of land millions of years ago allowed organisms from North and South America to cross into new environments. Today, humans bring animals and plants to Panama from distant ports. Along the banks of the canal, invasive species separated by millions of years meet—elephant grass native to South Asia slowly encroaches on fossils that reveal new information about our planet’s past.

Panama today is an isthmus (or land bridge) connecting North and South America. Image from freeworldmaps.net.

Lay of the Land

Panama’s geology is crucial to this story of species migration. Before it was an isthmus, Panama was a peninsula jutting off of North America. Between 21 and 18 million years ago, the distance between North and South America was about 124 miles (200 km) and covered in deep seas. The sediments along the canal reveal a series of drastic transformations during this time: underneath volcanic basalt, paleontologists have uncovered a shallow marine environment sandwiched between two terrestrial layers. These layers tell scientists that within the span of a few million years this region was first above sea level, then underwater, then above sea level again, and later covered in lava—all due to tectonic activity. Fast-forward to 1914, when the landscape again changed dramatically (this time thanks to humans): where a land bridge once separated two oceans, the United States government divided the continents by completing a series of canal locks connected by an enormous artificial lake.

Past Invasions

Around three million years ago, land animals migrated in earnest across the Isthmus of Panama. Scientists call this the Great American Biotic Interchange (or GABI). Camels, elephant-like gomphotheres, tapirs, deer, foxes, rabbits, bears, peccaries, and cougars moved into South America while large flightless birds, giant ground sloths, capybaras, armadillos, porcupines, and opossums came north. This migration totally changed the face of the fauna on both continents—in fact, many animals that we think of as stereotypically South American (such as llamas) actually have North American origins.

The rocks along the canal are at least 15 million years older than GABI, so scientists expected to find North American animals like horses, camels, bear-dogs, and raccoons. They didn’t expect South American species, but that is what they are now unearthing. Take the 19.3 million year old boa fossil they found. Boas can swim, but crossing a 124-mile (200 km) seaway is an impressive feat. How did it get to Panama? Did it “island-hop,” or raft across on storm-swept debris? Or was there an older, more solid connection between North and South America? Fossils like this one are pushing back the timing of the formation of the isthmus, and making scientists re-evaluate past assumptions about when and how species migrated.

Paleontologists in hard hats and safety vests walk along the banks of the canal, eyes down, scanning the ground for fossils from the Cascadas Formation. Photo by Juliana Olsson.

Present invasions

Understanding how ancient animals fared in new environments is relevant to our world today because so many plants and animals follow on the heels of humans. These species change ecosystems wherever they’re introduced. For example, elephant grass, or canal grass, grows everywhere along the canal. No one seems to know when it was introduced, though canal workers might have planted it to control erosion along the banks of the original canal cuts. Today it has become a pest: elephant grass is the first plant to appear in new clearings, driving out the native pioneer communities. One scientist is actually doing genetic research to determine if all the grass came from a single introduction or represents multiple arrivals. But that’s a story for another day!

Here on the banks of the Panama Canal the present tangles with the past. Elephant grass—a recent invasive—grows so quickly that it covers the fossil dig sites on the banks of the expanded canal. Paleontologists have only a narrow window of time to recover fossils before the plants take over again and cover the past for good.

The far bank of the canal is already overgrown with grasses and shrubs. Photo by Juliana Olsson.

By Juliana Olsson, Exhibits Writer/Editor, National Museum of Natural History

01/28/2015

Smithsonian postdoctoral researcher Neil Kelley studied the skulls of marine mammals and reptiles to learn about the evolution of feeding strategies in these animals. Image by Nicholas Pyenson, Smithsonian Institution.

A friend and I were recently trying to decide on what to eat for lunch. He asked, “do you like sushi?” Is that even a question? I love sushi, good sushi. No cuisine provides a better opportunity to sample the great diversity of food from the sea. Of course, there is the fish: salmon, albacore, eel. But there is so much more: seaweed, fish eggs, crab, clam and even sea urchin if you are feeling adventurous.

As a Peter Buck postdoctoral research fellow in the Department of Paleobiology at Smithsonian’s National Museum of Natural History, I study the evolution of animals that have evolved a similar taste for seafood. Just like humans, many different groups of land animal have learned to take advantage of the ocean’s bounty. Some of these land animals have evolved to become dedicated ocean dwellers, giving rise to marine mammals–like whales, sea cows and seals–and marine reptiles–like sea turtles and marine iguanas.

Our modern oceans are not unique in hosting these interlopers. While dinosaurs ruled the land in the Mesozoic (about 250 to 65 million years ago), the oceans were colonized by animals with terrestrial origins: for example fish-shaped reptiles called ichthyosaurs, long-necked plesiosaurs, and gigantic swimming lizards called mosasaurs. I am especially interested how these animals, living and extinct groups descended from land-dwelling ancestors, were able to find a place in ocean food webs. Were they predators or herbivores? Did they eat everything in sight, or were they specialized to eat a narrow variety of foods?

Marine iguanas (Amblyrhynchus cristatus) and manatees (Trichechus manatus) are descended from land animals, but both have adapted to feed on ocean plants. Similarities in the skulls of these animals reflects this similar diet. Image by Donald E. Hurlbert, Smithsonian Institution.

To test the hypothesis that the anatomy of living marine mammals and reptiles is closely tied to their diet, I combed through scientific studies of the diets of 69 different marine species, including whales, seals, sea cows, sea turtles and others. I then took detailed measurements of the skulls and teeth from these species using the Smithsonian’s extensive collections of mammal and reptile skeletons. I also visited museums in California, including the California Academy of Sciences, UC Berkeley Museum of Vertebrate Zoology and UC Davis Museum of Wildlife and Fish Biology, and the Royal Ontario Museum in Toronto, Canada to expand my dataset.

Manatee. Image by Chip Clark, Smithsonian Institution.

I found that skull and tooth shape very closely match the known diets of living species. Also, species with similar diets–for example sea turtles, sea cows and marine iguanas, which all eat marine plants–show similarities in skull shape despite being descended from very different ancestors. However, within some groups, closely related species have evolved to take advantage of different resources. For example, crabeater seals in Antarctica have specialized teeth for straining krill, while closely related leopard seals have evolved massive skulls and sharp teeth allowing them to feed on a wide range of prey including fish, crustaceans, and penguins.

I am now applying these results to better understand the evolution of diet and feeding styles in extinct marine reptile groups. This work will help to reveal how forces such as climate change and mass extinctions have transformed ocean ecosystems through time, and created evolutionary opportunities for land animals with a taste for seafood.

You can read more about the ecology and evolution of marine mammals and marine reptiles in our paper published this week in the journal Biology Letters.

Editors note: Special thanks to Dr. Ryosuke Motani, Department of Earth and Planetary Sciences, University of California, Davis.

By Neil P. Kelley, Peter Buck postdoctoral research fellow, Department of Paleobiology, National Museum of Natural History

12/12/2014

If you want book recommendations, talk to scientists. They read. A lot.

Need proof? There are 11 libraries in the National Museum of Natural History. Apart from the main branch, most are connected to a specific research area and about the size of a large living room. There’s one dedicated to birds, another to minerals, and so on.

For the most part, the books are variations on a theme: life and the forces—geologic and other—that lead to evolution or extinction.

Some are macro in scope, others chronicle the fate of a single species or region. Humans make cameos in many of these narratives, either in the form of paleontologists searching for answers or humanity writ-large altering the planet we inhabit.

Like the fossil record itself, these books prompt you to contemplate the profound and the amusing. Richard Fortey does both in Trilobite! Eye Witness to Evolution (my favorite title). I found myself wanting to put these Fortey phrases on T-shirts or holiday cards:

“Without death there is little innovation. Extinction—the death of a species—is part and parcel of evolutionary change.”

“Naturally, there would have been no baby trilobites without sex. Sadly, we do not know as much as we would like to know about the sex lives of trilobites.”

(Trilobites, for the record, are those iconic segmented, flat marine fossils that lived long before dinosaurs. Like today’s insects and crustaceans, they were arthropods.)

So, whether you’re looking to start a paleo book club or for gift ideas for fossil enthusiasts, consider these reads—grouped broadly into themes. And for those of you who like to judge books by their covers, we've included a slideshow.

12/04/2014

In July 2013, the Deep Time exhibits team went to North Dakota’s Hell Creek Formation to collect 66-million-year-old fossils. These fossils will be on display in our new exhibition on the Last American Dinosaurs while our permanent Fossil Hall is being developed. This is the 8th post in a series about our experiences out in the field.

On day three of the trip, our team stood on and even tasted the Cretaceous-Paleogene boundary—recorded in a thin line of sediment deposited about 66.1 million years ago, marking the extinction event that wiped out the dinosaurs. Here, under the blazing summer sun, Sant Director and paleobotanist Kirk Johnson answered the question, “What do our visitors need to know about how scientists understand the world?”

In just a few minutes, he described five major advances in scientific knowledge that have occurred since the Museum opened in 1910. These “five big leaps” have revolutionized the way humans understand our planet, its long history, and the forces that shape life. These leaps are one reason that the National Museum of Natural History is updating and expanding the National Fossil Hall.

Plate Tectonics: Our understanding of the large-scale movement of the Earth’s outer layer (or lithosphere) expanded in the 1960s, when geologists combined older ideas about continental drift with newer findings about sea floor spreading and new crust formation along underwater mountain ranges. Taken together, the evidence indicated that the Earth’s surface is made up of numerous plates that move slowly, shifting over many millions of years. This motion generates earthquakes, creates mountain ranges, and leaves traces in the geological record that help scientists reconstruct Earth’s past landscapes.

Evolution and Genetics: Over the past 60 years, we have increased our understanding of DNA’s role as the building block of all organic life. In 1953, James Watson and Frances Crick described DNA’s double-helix structure; 50 years later, scientists completed a 10-year, $3 billion collaborative effort to map the human genome. Recognizing DNA’s role in evolution has fundamentally changed the way we look at biology, paleontology, archeology, medicine—and ourselves.

Deep Time: We’ve known for decades that the Earth is very old. But we couldn’t know exactly how old until fairly recently. In 1862, Lord Kelvin calculated the Earth’s age to be 20 million to 400 million years old, but by the 1920s scientists were putting the age in the billions. Now, thanks to our ability to use radiometric dating techniques, scientists calculate the Earth to be 4.567 BILLION years old (plus or minus 50 million years).

Climate Change (Past and Present): Over the billions of years of Earth’s history, the planet has warmed and cooled in cycles characterized by changing atmospheric chemistry. We know this partly from studying the fossil record—a fossil’s chemical composition changes depending on what the atmosphere was like when the organism was alive. But since the beginning of the Industrial Revolution 150 years ago, when we began burning large quantities of fossil fuels, the rate of climate change has become more extreme. Currently, atmospheric carbon dioxide levels are the highest they’ve been in 15 million years – and since carbon directly affects climate, this is a big deal. Our growing global population (7 billion and counting) and our desire for energy are contributing to climate change on a scale that hasn’t been seen before in human history.

Earth is Not an Island: It’s easy to forget the Earth is part of a vast universe with many, many factors over which we humans have absolutely no control. Advances in astronomy over the past century—not to mention the advent of human space travel—have provided huge amounts of data about what else is out there. For example, over Earth’s 4.567 billion year history, asteroids have hit our planet repeatedly. One of them caused the mass extinction that wiped out the dinosaurs.

In many ways, the things we found at Hell Creek exemplified these five big leaps. Spherules point to a massive asteroid impact. Crocodile bones and fossil palm fronds revealed that this region experienced a warmer climate in the past. We saw layers of rock that were 66 million years old. We compared and contrasted animal forms, including those of long-extinct dinosaurs. We looked out over marine deposits from an ancient inland sea that once covered North America’s Western Interior.

In fact, many of these themes will be apparent in our newly renovated Fossil Halls. When the National Museum of Natural History first opened its fossil halls in 1911, none of these scientific leaps had been made. Even as recently as 30 years ago, science hadn’t made the connection between carbon and climate change, and we had no idea just how dramatically an asteroid could impact life on Earth. There are so many exciting new stories to tell, and we can hardly wait to tell them. First up: the life, death, and discovery of dinosaurs from the Hell Creek Formation. This brand-new exhibition on the Last American Dinosaurs opened at the Museum on Nov. 25, 2014 and will remain on display while we renovate our fossil hall.

By Laura Donnelly-Smith and Juliana Olsson, Exhibits, National Museum of Natural History

11/21/2014

In July 2013, the exhibits team went to North Dakota’s Hell Creek Formation to collect 66-million-year-old fossils. These fossils will be on display in our new exhibition on the Last American Dinosaurs while our permanent Fossil Hall is under construction. This is the 7th post in a series about our experiences in the field.

We spent so much time last summer digging around the Hell Creek Formation, we thought it deserved its own blog post. In order to know where to find fossils, you need to know where to find the right rock formations, and for that, you need to know a bit of geology.

Formation Basics

Formations are recognizable rock layers or “strata,” and they vary from region to region. All formations have a particular size, appearance, and history. They can range anywhere from 10 to 10,000 feet in thickness, from 3 to 3,000 miles in area, and encompass thousands to millions of years of time. Geologists usually name a formation based on the location where it is best recognized as a distinct set of rock layers—the Hell Creek Formation was described after a rock outcrop along Hell Creek near Jordan, Montana.

Lots and lots of layers with different textures and colors. Photo by Kirk Johnson/ Smithsonian Institution

The Hell Creek Formation is sedimentary—good for us, since we were interested in finding fossils. Because sediments settle differently in different environments, geologists can distinguish between former lakes, streams, ponds, rivers, swamps, reefs, beaches, and sea-floors. Plants and animals that died in the area were sometimes buried in these sediments, and became fossils. The Hell Creek Formation was formed by sediments deposited in rivers, lakes, and floodplains from 68 to 66 million years ago, and preserves plenty of Late Cretaceous plants and animals.

Where to Look

To find the Hell Creek Formation in North Dakota, we searched along the exposed faces of buttes (small hills with steep sides and fairly flat tops that dot the western landscape). Geologic maps told us where geographically we’d find the Hell Creek Formation, but we still had to find sites where it was exposed in accessible outcrops. Time for an analogy:

Think of a stack of pancakes, with two blueberry pancakes on the bottom, four chocolate chip pancakes in the middle, and three buttermilk pancakes on top. Each flavor represents a new formation, and there are a varying number of thinner depositional layers within each formation. The oldest pancakes are on the bottom, while the ones fresh off the griddle are on top. Geology works the same way: newer things sit on top of the old. But it’s not always that simple…

Geologic forces from plate tectonics—such as volcanism and seismic activity—can fold and fracture formations. Imagine sliding your knife beneath your stack of pancakes and lifting upward, just as geologic forces might fold rocks to form a mountain. The stack will bulge up in the middle until eventually it splits, exposing cross-sections of all your different flavor formations. Similarly, if you started pushing up on the outside edges of your pancakes, you’d get a U-shaped stack: the sides will be tilted up, and you could see the exposed stack on the outside edges.

Now imagine that the chocolate chip pancakes in the middle are the Hell Creek Formation (the chocolate chips are fossils, of course), and that’s how paleontologists think about rock layers. Although it’s possible to drill down to find the layers you want to see, it’s much easier to go to the outer edges where tectonics have pushed them to the surface.

Let erosion do the work! We found lots of great plant fossils in the Hell Creek Formation layers on these buttes. Photo by Kirk Johnson/ Smithsonian Institution

Once we identified the Hell Creek Formation and started prospecting, we soon found what we came for—spectacular Late Cretaceous plant fossils and tiny animal bones, scales, and teeth. On November 25th, you’ll be able to see some of these fossils on display in our new exhibition, “The Last American Dinosaurs: Discovering a Lost World.” Our scientists and volunteers are also preparing some of these fossils for our future main Fossil Hall, opening in 2019.

By Juliana Olsson, Exhibits Writer/ Editor, National Museum of Natural History

11/14/2014

In mid-July of 2013, the exhibits team went to North Dakota to collect 66-million-year-old fossils from the Hell Creek Formation. These fossils will go in our new exhibition on the Last American Dinosaurs while our new Fossil Hall is under construction. This is the 6th post in a series about our experiences out in the field.

Scrambling around the rocks in North Dakota, we became familiar with the boundary between the Cretaceous and Paleogene periods of geologic time, which marks the end of the age of dinosaurs, 66 million years ago. You might remember that the Cretaceous/Paleogene (K/Pg) boundary is an important place-marker chosen by scientists, and it has distinctive physical features that can be found in different locations around the world.

Standing on the K/Pg Boundary, we found evidence of the Cretaceous extinction event right at our feet (literally). Photo by Juliana Olsson/ Smithsonian Institution

Boundaries Mark Important Moments in Time

Early geologists understood that rock layers formed in a sequence, with the oldest layers below the youngest ones. This allowed them to tell relative time in any particular place by looking at the order of the rocks. But there was no real way to tell absolute time, making it difficult to know whether one stack of rocks recorded the same sequence of events as another stack exposed hundreds or thousands of miles away. Identifying distinct global events would help geologists compare distant formations.

Fossils helped. Geologists knew that some fossils were found across wide areas, but only in specific layers of rock. This meant that the original organisms were widespread but only lived for a certain period of time. For example, dinosaur fossils are found in Mesozoic rocks but not older or younger layers, and they lived all across the globe. So their fossils could be used to constrain the age of their surrounding rocks. By using hundreds of different species to carefully correlate many rock layers, early geologists developed a remarkably detailed (and surprisingly accurate) time scale.

As a result, some moments in time became more important than others. The moment when dinosaurs became extinct was especially important because it took place everywhere at about the same time—so this event was used to mark the end of not just the Cretaceous Period but the entire Mesozoic Era.

Once radiometric dating was discovered in 1907, geologists could go back to these rocks and figure out exactly how old they were. Now we know that the Cretaceous Period ended when the dinosaurs went extinct, and that this took place 66 million years ago. With improvements in technique, we can now pinpoint this date to within a few tens of thousands of years—not bad for something that happened so long ago.

Geologists still use events to mark boundaries, precisely because they represent moments in time that were important across the world at the time they took place. But scientists now work to know when these events occurred as precisely as possible.

Time and Rock Formations

A formation is a recognizable layer of rock with a specific history and geographic range, typically named after the location where it was first identified. Formations have their own “boundaries,” called contacts, where they contact a younger layer (above) and an older one (below). But these are physical borders, and in fact one formation can change over to another at slightly different times in different places. Because they form under local geological conditions, formations often do not match exactly with geologic time periods (which are based on global events).

And that’s the tricky thing about boundaries and rocks: they are totally different things. The rocks preserve the boundary, but they are not interchangeable. The boundaries between geologic time periods take place at specific, absolute moments in time, and would exist even if we had no rocks to record it (thankfully, that’s not the case with the K/Pg boundary).

The physical signals of a boundary like the K/Pg are found in formations, but which formation depends on where you’re looking. In the Dakotas and Montana, the K/Pg boundary lies at the top of the 300-foot-thick Hell Creek Formation. This formation contains the rock layer that was the land’s surface when the asteroid hit. It also contains fossils that reveal the world of Tyrannosaurus and Triceratops. Come explore their world (and relive our expedition) in “The Last American Dinosaurs” exhibition, opening November 25th.

By Juliana Olsson, Exhibits Writer/Editor, and Matthew Carrano, Curator of Dinosauria, National Museum of Natural History

10/14/2014

That fixation would have brought me smack into the world of science in my formative years, when it was most important. Instead, I’ve been on the periphery of science my whole life. I want something different for my daughter—and for every child, for that matter. With that in mind and to celebrate National Fossil Day, we offer two interviews that star two dino-crazed girls: Charlotte and Tallulah.

Charlotte (Left), Tallulah (Right).

Interview #1: This is what curiosity sounds like. (audio-only)

In which 5-year-old Charlotte, of Virginia, speaks candidly about her passion for a certain king of dinosaurs with Smithsonian educator Amy Bolton.

Tyrannosaurus rex, by Charlotte.

Interview #2: Is it hard to become a paleontologist? (a Google Hangout video)

In which 8-yr-old Tallulah, of West Chester, Pennsylvania finds out what it’s like to be a paleobiologist by talking with a luminary in the field, Dr. A. Kay Behrensmeyer, of the National Museum of Natural History.

What about you? Were you ever a walking encycloped-a-saurus? Perhaps you still are. Tell us about YOUR dinosaur—or fossil insects, plants, whales, etc.—phase.

And tomorrow, on National Fossil Day take a few moments to reconnect with your paleo self, or, if you’re like me, cultivate a latent interest in the subject. While you’re putting on your shoes, riding the bus, or sitting at your desk, go ahead and take the Junior Paleontology Pledge:

“As a JUNIOR PALEONTOLOGIST, I promise to:

EXPLORE the ways that paleontologists work;

LEARN about Earth’s history, ancient life, and changes through time; and

PROTECT our public lands, including fossils and rocks in which they are found.

I also promise to have fun and share what I learn with my family and friends."

08/29/2014

Fieldwork is glamorous. Well, at least in the sense of discovering things first-hand; not usually in the sense of glamourous living conditions! However, paleontologists and archaeologists often make exciting discoveries in museum collections too. My name is Briana Pobiner, and I’m a prehistoric archaeologist in the Human Origins Program in the Department of Anthropology at the Smithsonian’s National Museum of Natural History. I just returned from Kenya, studying fossils in the Paleontology Division of the Nairobi National Museum excavated from the Smithsonian-National Museums of Kenya prehistoric research site of Olorgesailie.

The Smithsonian excavations at Olorgesailie have taken place over nearly the past 3 decades, so part of what I get to do is open bags with fossils in them that have not been opened since the day the fossil was excavated in, say, 1988 – when I was 13 years old!

Needless to say, there is a lot of dust on these fossils, so I wear a lab coat to keep my clothes from getting filthy every day. Still, after a few hours, my hands are really dirty!

My main research focus is on prehistoric human diet, so I’m examining the animal fossils for evidence of human butchery in the form of marks left by stone knives. But part of the overall research at Olorgesailie is trying to understand how early human behavior – including animal butchery, plant processing, and stone toolmaking – varied over a larger landscape. To do this, the team excavated many sites in a single time horizon – in this case, that horizon is 990,000 years old. Part of reconstructing what that landscape looked like involves identifying the species of animals found in the excavations. I have been studying these fossils since 2004, and according to my Excel database, I have already studied 56,856 fossils before this year’s research commenced!

Every bone is important in these kinds of analyses. Out of the dozens of thousands of animal bones from the 990,000 year old layers of sediments at Olorgesailie, we have only identified one giraffe tooth.

Detailed view: comparing the fossil tooth to the modern giraffe tooth.

This is really interesting because most of the fossil animals from this layer are grazers (they eat grass) – like zebras, white rhinos, and certain species of antelope – implying that there was a lot of open grasslands around Olorgesailie at this time. But giraffes are browsers; they eat leaves from trees. So this single giraffe tooth tells us that there were also trees in the general vicinity of Olorgesailie. You can see Dr. Rick Potts, the director of the Human Origins Program at the Smithsonian and of the Olorgesailie research project, and I were very happy to confirm that this tooth is indeed from a giraffe by comparing it to a modern giraffe tooth in the Osteology Division at the museum.

Images and text by Dr. Briana Pobiner, prehistoric archaeologist in the Human Origins Program, Smithsonian’s National Museum of Natural History

09/10/2013

In mid-July of 2013, the Deep Time exhibits team went to North Dakota to collect fossils. Our goal was to find 66-million-year-old fossils from the Late Cretaceous for our new exhibitions, and to learn more about paleontology. This is the first post in a series about our experiences in the field.

The Hell Creek Formation is a microfossil treasure trove— if
you know what to look for. Photo of Abby Telfer
collecting microfossils. Photo by Kay Behrensmeyer, Smithsonian Institution

Before our trip, many exhibits team members had no field
experience. Luckily, we could turn to our curators for advice and
encouragement. They helped us learn what
to look for and where, and how to identify fossils.

How do professional paleontologists know something is a
fossil? Years of practice! But even with a little experience around fossils,
you’ll have an easier time picking one out from a pile of rock by looking for
three traits:

1. Color

The black and grey fossil bone fragment on the left
is a different color than the surrounding reddish rocks. It is also denser than
the weathered modern bone on the right. Photo
by Juliana Olsson, Smithsonian Institution

Fossils tend to have a different color from the surrounding
rock. They may be lighter than the rocky substrate, or they might be darker –
it all comes down to the weathering process, and the fossil materials. Plant
fossils are almost always darker than the rock in which they’re found. If
you’re searching for microfossils on the ground, they’ll probably be a lighter,
almost creamy color since they have been exposed to the elements—though teeth,
claws, and scales are dark and glossy.

2. Texture

This piece of turtle shell embedded in the rock has
a distinct, dimpled texture, which makes it noticeable even though it’s only
about 4 cm wide. Photo by Kay
Behrensmeyer, Smithsonian Institution

Bones are more porous than rock, and this texture difference
makes them easier to spot. Because of its “spongy” texture, if you touch a
fossil to your tongue it will typically stick, whereas rock and soil won’t. If
you’re not in the mood to do the tongue test, you can also look for pores through
a hand lens.

Some bone patterns can tell you who the original owner might
have been. Turtle shells have little pits and grooves on one side. Crocodile scutes
have even more pronounced pits, and sometimes a little ridge in the middle.
Young and old members of the same species differ in the growth patterns on
their bones, a fact which can help scientists determine the biological age of a
fossil. Sometimes bones even have little marks on them where muscles used to be
attached.

3. Shape

If you’re lucky, the item’s shape will be an even bigger
clue. While many bone fragments are unidentifiable, there are many bones that
are highly diagnostic for an entire group of animals, if not for a species.
These diagnostic bones tend to be things with complex shapes, like vertebrae,
skull bones, and even teeth and claws. For plants, the diagnostic features tend
to be the leaf edges and bases, as well as the pattern of veins.

The fossils we found came in a wide variety of
shapes, from blade-like gar scales (box at bottom right), to oval fish
vertebrae (above the gar scales), to pointy conical teeth! Photo by Kay
Behrensmeyer, Smithsonian Institution

Distinctive bones aren’t the only fossils with easily
identifiable shapes. Coprolites (fossil poop) look the way you’d expect them
to, and tend to be a little bit lighter than the rocks around them. Casts,
molds, and steinkerns (internal molds) look like the original organism;
mollusks and other animals with shells are often preserved this way.

If you spend even a short time looking for fossils, you’ll
learn how to tell that the thing in your hand is a vertebra or a root. But to
know what genus it belongs to, you’ll have to spend some time handling fossils
and doing research. Generations of scientists have taken the time to describe
in detail the anatomy of animals past and present, and you can compare your
fossils to these descriptions. You can visit university websites like UCMP for more information on
identifying fossils, volunteer at your local prep lab, or come see our fossil
exhibits in person. You can also follow Deep Time at the
Smithsonian (or the NMNH Facebook
and Twitter feeds) for more on fossils
and updates about the exhibit.

by Juliana Olsson, NMNH Office of Exhibits Writer with the support of Angela Roberts and Siobhan Starrs